With proposal of global environmental protection, saving energy has become a trend of developing an industry. In recent years, LED industry is paid more and more attention. So far, LED products have advantages of low power consumption, high light emitting efficiency, fast response time, long lifespan, exempting from mercury pollution, and benefitting environmental protection, and so on. In particularly, with the development of the high-power high-brightness light emitting diode (HB LED), LEDs are widely applied to an illuminating light source, a backlight of a display, a lighting device of an automobile, and a lighting device of a mini projector.
FIG. 1 is a schematic, cross-sectional view of a conventional LED assembly. Referring to FIG. 1, an LED assembly 100 includes a heat sink 102. A dielectric layer 110 is formed on an upper surface 104 of the heat sink 102. A patterned electrically conductive layer 112 is formed on the dielectric layer 110. A material of the patterned electrically conductive layer 112 can be copper. A solder paste 122 is disposed between an electrode 118 of an LED chip 116 and the patterned electrically conductive layer 112. The LED chip 116 is electrically connected to the patterned electrically conductive layer 112 through the solder paste 122.
In the conventional LED assembly 100, when the LED chip 116 emits light, heat generated from the LED chip 116 is transferred to the heat sink 102 through the solder paste 122, the patterned electrically conductive layer 112 and the dielectric layer 110 in sequence. Thus, the heat dissipation efficiency of the conventional LED assembly 100 is not satisfying, thereby affecting the light emitting efficiency of the LED chip 116.